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Monday, April 2, 2012

Flowing Water on Mars? Strange Red Planet Features Stir Debate

The only thing not flowing is the truth of what is going on on Mars. Mars has activity and life, some very strange life and not so strange like the Wookiee. Not only are scientists keeping a tight lid on what mars is but so is the media. No one wants to rock the cradle and wake up the sleepy-heads.

Flow-like features on Mars are a source of debate among
scientists. While some experts say they are likely produced by liquid water or
brine on the Red Planet's surface today, other investigations interpret some of
these features as dry mass movements, stirred up by various other processes.

Many scientists agree that water likely flowed across ancient Mars. However,
whether it exists as a liquid on the planet's surface today is arguable.

Recurring Slope Lineae are dark, narrow features that extend on steep,
equator-facing, mid-latitude rocky slopes of Mars. Furthermore, they form and grow during multiple
warm seasons, and fade in cold seasons.

The head-scratching phenomenon sparked a lively debate on what's behind the
strange slope processes on Mars during last week's 43rd Lunar and Planetary
Science Conference in The Woodlands, Texas. [Photos: The Search for Water on Mars]

SPACE.com spoke to several scientists involved in the research, who gave us a
glimpse into what may be happening on Mars.

Ongoing drainage system

Conditions are such on present-day Mars that, at certain locations at certain
times of year, liquid water should be capable of existing for short amounts of
time, according to Jim Head and Jay Dickson of the department of geological
sciences at Brown University in Rhode Island.

The best evidence that water currently exists there comes from the recent
discovery in the southern mid-latitudes of Recurring Slope Lineae, or RSL for
short.

Dickson and Head described their research findings, showing that identical
features are found on the equator-facing wall of the South Fork of Upper Wright
Valley in the McMurdo Dry Valleys of Antarctica.

"If this is correct, then RSL on Mars may represent the surface expression of a far more
significant ongoing drainage system on steep slopes in the mid-latitudes," the
team said.

Islands of persistence

In research led by Norbert Schörghofer, of the University of Hawaii's
Institute for Astronomy in Honolulu, a selected study site on Mars revealed the
coming-and-going nature of slope streaks.

"For the first time we see an approximate balance between faded and new
streaks," Schörghofer said. "The rate of formation and rate of fading are nearly
equal, revealing that the number of slope streaks on the surface of Mars is approximately constant rather than
increasing with time. This indicates the streak population is balanced."

The average lifetime of slope streaks, from time of formation until they
disappear, and the turnover time of the slope streak population, are estimated
to be four decades, Schörghofer said. Slope streaks fade gradually over time,
with "islands of persistence," and are not obliterated by planet-encircling dust
storms.

Rolling and tumbling

So, what on Mars is actually going on?

A formidable tool in helping to spot and catalog these confounding features
is NASA's Mars Reconnaissance Orbiter, or MRO, now circling the Red Planet.

"This is complicated," said Alfred McEwen, a planetary geologist and director
of the Planetary Image Research Laboratory at the University of Arizona in
Tucson."Lots of stuff moves down steep slopes on both Earth and Mars." McEwen is
principal investigator of the High Resolution Imaging Science Experiment
(HiRISE) on the MRO.

On Mars, there are several rolling and tumbling categories, McEwen told
SPACE.com:

Slope streaks on dusty equatorial slopes. These are fully explained as dust
avalanches.

Slope streaks associated with the presence — especially defrosting — of
carbon dioxide (CO2) frost, so CO2-aided mass wasting explains this. This
category includes active gullies. The only distinction is whether or not HiRISE
images can resolve the topographic changes.

Lineaments associated with dry boulder/debris falls.

Recurring Slope Lineae may look superficially similar to the other
categories, but form only under very particular environmental conditions, in
places where there is no CO2 frost. They grow incrementally, and they recur each
summer. So far, only the flow of briny water seems to be able to explain
these.

"Folks can invoke water for all of the above if they like water. But given
the thermodynamics," McEwenadded, "it is extremely unlikely except, maybe, for
the RSL. They all have excellent non-water explanations except the RSL. Maybe
the RSL will eventually prove to have a dry explanation as well."